Demand for integrated circuits (ICs) in portable electronic applications has motivated greater levels of semiconductor device integration. Many advanced semiconductor devices in development leverage non-silicon semiconductor materials, a subset of which have hexagonal crystallinity. One class of those materials is transition metal dichalcogenides (TMD or TMDC). Similar to graphene, TMDCs display semiconductor properties as a monolayer sheet of MX2, where M is a transition metal atom (e.g., Mo, W) and X is a chalcogen atom (S, Se, or Te). In the monolayered crystalline sheet, one layer of M atoms is disposed between two layers of X atoms. TMDC materials are of significant interest as a basis for highly-scaled integrated circuitry (IC), in part because of the thin active layers possible. For example, a semiconducting MoS2 monolayer has a film thickness of only 0.65 nm. A TMDC-channeled transistor would therefore have excellent short channel properties and gate electrode control. Unlike graphene, TMDC materials have been found to have a bandgap (direct) suitable for both transistors and optical devices. It has also been shown that many TMDC materials have good electron and hole mobility, which again makes them interesting for highly-scaled short channel devices (e.g., Lg<20 nm).
However, high-quality growth processes for TMDC compounds have been absent from the literature. To date, most TMDC materials have been obtained through non-manufacturable techniques like exfoliation (e.g., scotch tape liftoff). A few other techniques, like deposition on amorphous materials (e.g., SiO2), at best yield polycrystalline films, which do not yet display satisfactory device performance.